Exactly 15 months ago Friday, eight Americans were in a meeting room on an Afghan military base, planning the future of that country.

Then gunfire rang out. An Afghan pilot began shooting, killing all eight Americans in the meeting and one more who ran from another room into the hallway to help.

They were "air advisers," eight active service members and one retired Army lieutenant colonel. Their goal was not to design bombs or plan attacks, but to guide Afghans as they built their air force to defend their own country.

Friday, hundreds of family, friends and fellow service members gathered at Joint Base McGuire-Dix-Lakehurst, where the fallen all once trained, to dedicate a memorial outside the U.S. Air Force Advisor Academy to Lt. Col. Frank Bryant Jr., Maj. David Brodeur, Maj. Jeffrey Ausborn, Maj. Raymond Estelle II, Maj. Phil Ambard, Maj. Charles Ransom, Capt. Nathan Nylander, Master Sgt. Tara Brown and Ret. Lt. Col. James McLaughlin. Nylander was the officer who ran into the gunfire to try to stop the shooter.

Questions remain about their deaths, specifically the motive behind the shooting spree — the killer apparently killed himself soon after — and the possible complicity of other Afghans in the room.

Air advising is a delicate dance that forces advisers and those they are helping to quickly develop trust, Maj. Gen. David Allvin said at the dedication ceremony.

"We ask them to advise, to train, to occasionally educate," he said, while also attempting to understand the host nation’s culture. That’s something, he said, that advisers cannot "delude" themselves into thinking they completely understand.

For advisers to be effective, Allvin said, they must extend an open hand, not a combative closed fist, to build relationships with their hosts.

The memorial, two A’s for "air adviser" built of stone and entirely funded by private donations, expresses that relationship and how it is made "from the ground up, brick by brick," said Col. Olaf Holm, who spearheaded the project.

In its spot beside the U.S. Air Force Air Advisor Academy on the base in southern New Jersey, the memorial provides a place for both reflection and inspiration to those training to become air advisers, Allvin said.

A small waterfall makes the horizontal line of the larger A, its soft sounds muting the quiet crying of the crowd Friday morning as their husbands, fathers, sons, friends, fiance and wife were remembered. They clutched rubbings of plaques placed on the stone wall, with the names of those killed etched on them, and stepped over bricks with personalized messages.

"I didn’t understand a whole lot of what he did until today," Laura Levy, McLaughlin’s niece, said after the ceremony. "I’m glad that people are willing to dedicate their lives to that."

McLaughlin, of Somers Point, was a retired lieutenant colonel and was working in Afghanistan as a contractor when he was killed.

For Ret. Lt. Col. Sally Stenton, the act was a "huge betrayal." Stenton, a legal air adviser from Cherry Hill, who was about 200 yards away in another building, called the shooting "the worst day of my life."

"It completely changed how we look at things," she said. "I couldn’t trust them the way that I used to."

When officers knocked on Janice Bryant’s door in Arlington, Va., to tell her that her husband was dead, she closed it on them.

Bryant said just moments before she had felt "in my heart" that her husband was okay.

"But he wasn’t," she said.

Their son, Sean, now 2, is the spitting image of his father, according to Bryant.